Both ethyl acetate and acetaldehyde are feedstock chemicals of some economic importance. There are many sources of dilute ethanol wastes such as the brewing industry, biomass conversion processes and processes for fermenting cellulose and hemicellulose currently under consideration. Economical recovery of these ethanol wastes by, for example direct extractive fermentation, selective membrane fermentation, vacuum fermentation, adsorption/desorption, electrochemical oxidation or in the form of valuable chemicals such as ethyl acetate and acetaldehyde, is of interest. T. M. Meshbesher, in U.S. Pat. No. 4,347,109, describes an electrochemical method for making acetaldehyde from ethanol. D. W. Armstrong et al, in Biotechnol. Bioeng. 25, 2567-2575, 1984, have shown that dilute ethanol can be converted to ethyl acetate by Candida utilis but that higher concentrations of ethanol were strongly inhibitory (both dilute and higher concentrations of ethanol being less than 10%). The production of acetaldehyde from such microorganisms and an ability to switch, at will, from the production of acetaldehyde to ethyl acetate and vice versa, may prove useful especially where dilute alcoholic wastes are produced and provide means for conveniently switching from the production of one compound to the other as desired.